package cn.ex;

public class Ex4 {
    public static void main(String[] args) {
        String str = "java123";
        String s = "";
        for(int i=0;i<str.length();i++){
            s = str.charAt(i) + s;
        }
        System.out.println(str);
        System.out.println(s);

        StringBuilder sbu = new StringBuilder(str);
        System.out.println(sbu);
        System.out.println(sbu.reverse());
    }
}
